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Arxiv: Emission-Line Ratios and Ionization Conditions of CEERS Star-Forming Galaxies with JWST/NIRSpec Published: 10/3/2024 9:00:00 PM Updated: 10/3/2024 9:00:00 PM

Paper abstract: Galaxy emission-line fluxes can be analyzed to determine star formation rates(SFR) and ISM ionization. Here, we investigate rest-frame optical emissionlines of 71 star-forming galaxies at redshift 0.7 < z < 7 from the CosmicEvolution Early Release Science (CEERS) survey using JWST/NIRSpec. We useH{\alpha} line fluxes to measure SFRs. We combine these with HST CANDELSstellar mass estimates to determine the redshift evolution of specific SFR(sSFR) and compare our sample with the star-forming galaxy main sequence. Wecreate [O III]{\lambda}5008/H{\beta} versus [Ne III]{\lambda}3870/[OII]{\lambda}3728 line ratio diagrams and correlate these ratios with sSFR andthe distance of each galaxy from the main sequence (excess sSFR). We find amodest correlation between the line ratios and sSFR, which is consistent withprevious work analyzing similar samples. However, we find a weak correlationbetween the line ratios and excess sSFR. Taken together, our results suggestthat sSFR is the parameter that governs ionization conditions rather than SFRor a galaxy's distance from the main sequence. These measurements reveal a richdiversity of ISM conditions and physical galaxy properties throughout cosmictime.